<!DOCTYPE html>
<script>
    window.onload = function() {
        document.body.offsetTop;
        document.getElementById('elm').style.display = 'none';
    }
</script>
<p>There should be a blue <em>square</em> below.</p>
<div style="display:table; border-spacing:100px; background:blue;">
    <div style="display:table-row-group;"><div id="elm"></div></div>
    <div style="display:table-row-group;"><div style="width:10px; height:10px;"></div></div>
</div>
